Spot-welding machine.



E. THOMSN.

SPOT WELDING MAOHNE.

APELIGATIQH FILED 11H10. 1013A lll-Nil@ @Tr-i" lllS Pifll operon 'rino wnnniueooivrrnnr. or LYNN,

MASSACHUSETTS.

MASSACHUSETTS, A CORPORATION OF SFOT-VELDXNG MACHINE.

Application filed Moy l0, 1913.

Specification ot' Letters Patent.

Pat ont ed Jan. 20, 19t-1.

Serial No. 766.730.

is a specification.

tric welding machines My invention relates to that class or elecknown as spot welders. In 'this class of machines as ordinarily constructed the spot welding electrodes, by which. the Welding pressure is applied at the point of the worlr 1(there the weld is to he formed between the plates or sheets of metal, are mounted on the end of rigid arms eX- tended from the base or pedestal which carries the transformer, the space or opening between said arms forming the throat'. or opening to accommodate the work and permit a Weld to he readily made at any desired point on the same. This Vtoi-m ot" machine makes it necessary to employ a` heavy construction, the expense of `which it is one of the objects of my invention to avoid, A

ln my improved ctmstruction the welding electrodes are carried or supported in line with the transformer, the latter being mounted in the usual or any desired manner upon the pedestal or other suitalftle portion of the machine. @ne terminal of theI transformer is projected directly upward'as one ot the welding electrodes tired in position though it may he made to down for adjustment of height. The other elect-rode, which 1n ay he made. to move 'for the purpose of applying pressure, is mounted above the first suhstantially in line with the same andthe transtormeris connected with the opposite pole of the latter so as to torm in effect th terminal ther-ent. hy a lexihle ccnductor vhich extends away from the transformer and pedestal transversely and then hack for connection to the upper terminal or electrode, so as to shunt the gap or space corresponding to the throat or opening provided in the previous 'forms of machine by d arms l 'ore referred to. The said conductor may he ottany form but trence made of strips of copper on one another and properly atgid terninal ot the secondary e or bloc supporting or carryahle electrode. The conductor7 ino v telescope up and however. instead oft being made ot' lamina may he an ordiintry corulurting cable or a unuiher of cables running in parallel 'troni the terminal ol' the transformer to the electrode. For supporting the electrode torming the terminal ot' this laminated or other construction of conductor shuntingthe gap any desired construction may be employed. lhus, i'or instance, il may he supported on the end ot a comparatively light pivoted arm carried hy a standard or it may he sustained from a ceiling above the machine if the ceiling is not too high and the door space is valuable.

Figure l in the accompanying drawings is a side elevation of a form of machine embodying my invention. Fig. Q is a plan thercot'. Fig. 3 is a side elevation of a. modification in the manner of supporting thc upper electrodez l is a pedestal or support for the welding transformer. Said transformer is preterahly closed or boxed in a case, the detachable 'front plate ot which is indicated at Q.

3 indicates in dotted lines the transformer secondary made ,tor convenience and rigidity as a. casting, while #l indicates the usual laminated core ot the transformer. The primary may he disposed with relation to the secondary and core in any desired manner but inasmuch as the transformer itself lorms no part ot my invention the details oi construction ot the latter are not particularly descrihed herein. l

'lhe transformer primary toil is indicated hy the numeral 5. The transformer is solidlyv supported in any proper manner on t'ipedestal and in such way that pressure may he applied lo any desired amount in thc welding operation without dislocation oft the parts thereof.

(5 indicates the lower welding electrode projected upward from one end of the secondary 5 and constructed and attached to its support in an)vr desired manner. The Opposite terminal i ot the secondary extendingthrongh the casing or not as desired 'for convenience or attachment of the cable or conductor referred to has the said cahle,c.on ductor or pile oit laminte 8 suitably bolted to it in a manner to iornt a good joint.

The upper welding eiectrode il vvhich cooperates with electrode (3 is carried hy the lever l0 'fulcruuied ai, 1l. on a separate lill column or support 12. The Weight of said lever and. electrode may be counter-balanced by a suitable weight or spring 13 and said lever may have a forward projection 14 to form a handle for use ot' the workman in the weldingl operation. The electrode may be carried and fixed in a socket 15 by meansef a set screw 1G to permit adjustment or detachn'ient of the same or may have any other' adjustments for alinement or otherpurposes. l'hc extreme end ot' the cable or conductor S which extends around the zgap may be secured to the block or socket 15 by boltinp,- to an ear or projection from the same or may be otherwise electrically connected to the electrode t), so that the latter will form in effect a terminal of the transformer secondary. The conductor 8 is preferably continuous from point of attachment 7 to point of attachment 15 and is flexible at its bend to permit :tree movement of the upper` eleotrode in the Welding operation.

is will be obvious, the guiding or supporting lever, being required to support only the electrode and the conducting parts, may be of light construction and thin steel may be used for the purpose in place of the heavy castings employed in the previous construction `for the arms which project from a pedestal o r base and carry at their terminals the welding electrodes.

In the construction shown a pair of levers is employed with braces between to give lateral rigidity.

In the modilication of my invention shown in Fig. 3 the movable electrode in,- stead of being carried by the lever sustained at one side of the machine, is mounted in an overhead frame or hanger 17 secured to the ceiling. Said electrode is carried by a plun ger or rod 18 guided in said frame and its Weight is preferably sustained in part by a spring 19 suitably applied as indicated. Connection is made with the electrode 9 as bel'ore by means of the conductor shunt-ing` the ga p or throat for the Work, the two electrodes of the machine being arranged in line with one another and with the transformer and pedestal 1. The electrode may be operH ated :t'or Welding purposes by appliances l similar to those used for feeding a drill in an upright drill press and as indicated by the raelr on the side of the plunger, 'which is en. gaged by the segment 20 carrying the operating handle 21.

lt will be .seen that electrically the construction is the same as the previous con struction of spot welderin which the transformer is located at the base of the throat or opening and rigid arms and connectionsl extend therefrom laterally to the electrodes mounted on the end of said arms. But in my improved construction the electrodes and transformer are substantially in line withv one another and the throat or opening for the work is `provided by the tiexiblc conductor, the bend or" which is the bottom or base of the throat.

lt is obvious that the construction permits the ready substitution of cables or conductors of different length or depth of opening -or throat to accommodate work of different sizes. With very small work, that is with plates or sheets oi' small superficial extent, a very short length of' cable or conductor may be employed on the saine machine by simply detachmg the longer conductor at the points of attachment to the transformer terminal 7 and upper electrode and substituting the shorter one with some conseqmint advantage in the consumption of powenl Vhat I claim as my invent-ion is:-

1. In a'spot Welding machine, the combinationpwith a transformer of a weldin electrode forming one terminal thereo and mounted in line therewith and a conducting extension fromI the otner terminal of the transformer secondary projected laterally and extending baci: -tor attachment to Vthe opposite electrode to shunt the gap provided tor the Work, the support tor said opposite electrode beinplocated outside the gap pro vided by said conducting extensiorn 2. In an electric Welding machine, the combination with a transformer mounted on a. suitable pedestal or support and having one terminal of the secondary projected up- Ward as a Welding electrode ixed 1n position, of a second electrode movably supported above the same, a flexible extension from the other electrode or terminal of the trans* former led o'l' therefrom. in a way to shunt the gap and terminating in and fixed to said movable'elect-rode, and a sueport for said second electrode located outside the e' provided by said extension.

3. In an electric Welding machine, the combination substantially as described with a transformer mounted on a suitable perles tal or support and having one pole 'ontermina-l o its secondary terminating in a lired' Welding electrode, ot a laminated conductor attached to and extending laterally Iirma the opposite pole or terminal of the transformer secondary and back to position over the transformer so as to form the throat or'gap for the Work and a. Welding electrode mounted over the transformer and connected to the end of said conductor, the support for said electrode being located outside the gap provided by said laminated conductor.

4. In an electric welding; machine, the combination substantially as described Qta transformer suitably mounted on a suitable pedestal or support and having a fixed Welding electrode as one terminal or pole of the secondary, a second Welding electrode mount'- ed over the latter and carried by a frameor support independent of" the transformer sup,- port or pedestal and a iexibleconnection secondary, 'a 1 o'.

from the pole orfterniinalof the transformer gap or throat for the Work and having'its.lv

ends fastened respectively to theV opposite.v terminal of the transformer secondary'and to thevconducting base or block carrying said second electrode.

Signed at Lynn in the county of Essex and State of Massachusetts this 2nd day of 20 May A. D. 1913.

ELIHU THOMSON.

lVitnesses:

JOHN A. MCMANUs, J 1'., HENRY A. ANDERSEN. 

